2022-11-29 10:23:21

by Rao, Lei

Subject: [PATCH] nvme: clear the prp2 field of the nvme command.

If the prp2 field is not filled in nvme_setup_prp_simple(), the prp2
field is garbage data. According to nvme spec, the prp2 is reserved if
the data transfer does not cross a memory page boundary. Writing a
reserved coded value into a controller property field produces undefined
results, so it needs to be cleared in nvme_setup_prp_simple().

Signed-off-by: Lei Rao <[email protected]>
---
drivers/nvme/host/pci.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f4335519399d..488ad7dabeb8 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -797,6 +797,8 @@ static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma);
if (bv->bv_len > first_prp_len)
cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma + first_prp_len);
+ else
+ cmnd->dptr.prp2 = 0;
return BLK_STS_OK;
}

--
2.34.1

2022-11-29 13:44:54

by Christoph Hellwig

Subject: Re: [PATCH] nvme: clear the prp2 field of the nvme command.

Thanks,

I've applied the patch with a slightly update commit message to the
nvme-6.1 tree.